1. Field of the Invention
The present invention relates to a work transfer device used to mount an engine (engine unit) in a vehicle body in a vehicle production line, for example.
2. Description of Related Art
A conventional engine mounting device is configured by a main line assembling a vehicle and an engine mounting device (decking device), and the decking device includes a chassis preparing line assembling the engine and chassis (suspension system), and a mounting station mounting an engine assembly, which is assembled in the chassis preparing line and is mounted in a mounting carriage in a transfer station, in the vehicle in the main line.
The initial chassis preparing line is configured so as to place the engine and the chassis on an automatic guided vehicle (AGV), assemble the engine and the chassis together on the automatic guided vehicle, and assemble the assembled engine assembly to the vehicle with use of the decking device.
At this time, since a few dozens of automatic guided vehicles are required for the chassis preparing line, and the cost (value) of the automatic guided vehicle is high, a device constituting the chassis preparing line is disadvantageously expensive. Further, a large space for the waiting and travelling of the automatic guided vehicles is needed.
As shown in FIGS. 9A and 9B, a chassis preparing line 90 described in Japanese Patent No. 4170175 (Japanese Patent Publication No. 2005-66806) is configured so as to move a tool carriage 91 that mounts the engine and the chassis with an annularly-arranged driving chain 92, assemble the engine and the chassis together, and assemble the assembled engine assembly to the vehicle with use of the engine mounting device.
However, as shown in FIG. 9A, in the chassis preparing line 90 having such configuration, the tool carriage 91 travels on a frame 93, and the frame 93 is configured by integrating a body frame and a travelling frame. Accordingly, since the structure of the frame 93 is large, to change the chassis preparing line 90 with a change of processes, for example, increase the number of tool carriages 91, a major restructuring work of the frame 93 is required.
In addition, as shown in FIG. 9B, a driving part 94 feeding power to the driving chain 92 transmits a driving force from a driving motor 94a with use of a chain 94c having a particular structure, to which a slat plate 94b is attached, leading to an increase in costs of the entire device.
The present invention is made in consideration of the above-mentioned circumstances, and its object is to provide a work transfer device capable of moving a carriage in any direction and easily changing processes even with a simple configuration.